247 



mature, but dead in iiparl}' all parts, including the r o s) E — Immature wood of 

 varying tints. F — '' Bastard" (medium grade). G — Hed (tap roct of nearly dead 

 tree). H — Ked (tret! over ripe ; wood bored by ants). I — lie 1 (from r 'ots of 

 deadtiee). J — Red (best grade) 



More important, however than the variations in the shades of 

 colour in the extracts was the fact, ah'eady noted, that the sequence 

 of colouration intensity (in extracts made under like conditions in 

 detail in each series) varied with each solvent (TABLE IV). This 

 result not only shows that the colours of the woods are not due 

 merely to different amounts of the same pigment but also proves 

 that the pigmentary differences are caused either by varying pro- 

 portions of at least two pigments, or by the same pigment radical 

 in more than one chemical condition — in combinations, it may be 

 of different solubilities and stoichiometric relationships, and of 

 different dissociable tendencies. 



Relative tinctorial differences and variations are further shown 

 in the following sample data, which indicate the quantity of water 

 in c.c. added to 10 c.c. of Q.S% Na CO extract (TABLE IV) in order 



2 3 



to make the tinctorial intensity approximately the same throughout 

 the series.* 



The letters correspond to those in table iV. 



The tinctorial sequence after the above dilution is different from 

 what it was before dilution as may be seen from the following 

 summary : + 



•Dilution of D with an equal volume of water lurnished the bases of colouvatiou or 

 the ci'mpjirative observations. 



t This colour was of the same intensity as the rest, but not the sanje shade. See foot- 

 note above. 



X A. similar change in sequence of tinctorial intensity after dilution was noted in 

 other extracts, also. 



